Toca-5 gene therapy clinical trial fails

Tocagen, an American gene-therapy company, announced the trial’s failure yesterday.

Friday 13 September 2019

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The Toca-5 trial was a multi-centre clinical study consisting of 380 patients with recurrent high-grade gliomas.

The aim of the trial was to test the safety and efficacy of a gene therapy compared to the current standard of care.

Unfortunately, the phase 3 trial missed what is termed; ‘the primary endpoint of overall survival’ against the standard care treatment for such gliomas. To get so far in the process and not yield significant results for survival is a devastating blow.

It was hoped that this treatment would have a tremendous clinical impact, significantly increasing the survival of individuals diagnosed with recurrent high-grade gliomas. Sadly, this is not the case.

Tocagen’s gene therapy consisted of two drugs, Toca 511 and Toca FC, that have the ability to cross the blood-brain barrier and target the tumour cells. The drugs worked together, with Toca 511 containing a protein which has the ability to convert Toca FC to the anti-cancer drug, 5-fluorouracil that was hoped to lead to treatments for high-grade gliomas.

These brain tumours are aggressive and fast-growing with a high chance of recurrence. Patients with recurrent high-grade gliomas have a median survival of approximately seven to nine months.

We know that with such poor prognosis, there is a huge unmet need for treatments to improve the survival and quality of life of patients with high-grade gliomas.

There have been several clinical trial failures in recent months and it is heart breaking news for everyone in our community.

Dr David Jenkinson, our chief scientific officer, said: ”This is such disappointing news, one of several over the course of this summer. It demonstrates that we need to redouble our efforts and commission more research to help us understand this disease and continue to invest in new clinical trials.

“We call on everyone with an interest in this field to work together to ensure those affected are able to access therapies that may have an impact on the course of the disease.”

We are committed to investing in new research, knowing that we must support researchers to drive learnings from such failures to develop new treatments. Our recent investment of £2.8 million into The Tessa Jowell BRAIN-MATRIX
clinical trial is testament to this strategy.

This UK-led trial will have global implications for brain tumour patients and will pave the way for future treatments to be tested faster.

We understand that the news about Tocagen may be difficult for many and if you require additional information, please contact the Research Team

Alternatively, if you require support, please contact our Information and Support Team